Treating patella instability in skeletally immature patients.

PURPOSE: The purpose of this study was to comprehensively and systematically review the current evidence for orthopaedic treatment of immature and adolescent patients with acute and chronic patellar instability.

METHODS

We searched the online databases PubMed, CINAHL, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews for relevant publications on patellar instability. All dates and languages were included.

RESULTS

Twenty articles reporting on a total of 456 knees in 425 patients (131 male patients, 294 female patients) followed-up for 56.7 ± 42.2 months on average were included in the analysis. Two studies focused specifically on conservative versus surgical treatment in acute dislocations and reported no difference in outcomes after 7 and 14 years, even in the face of slight trochlear dysplasia. For recurrent instability, we found consistent beneficial effects from surgical stabilization on clinical scores, postoperative stability, and radiographic assessment. There is no evidence for growth disturbance with surgical patellar stabilization in immature patients.

CONCLUSIONS

The current best evidence does not support the superiority of surgical intervention over conservative treatment in an acute patellar dislocation. However, anatomic variations and their effect on healing should be considered and included in decision making. In recurrent patellar instability in pediatric and adolescent patients with normal or restored knee anatomy, reconstruction of the medial patellofemoral ligament (MPFL) is the most effective treatment option and can be done safely, together with extensor realignment as needed.

LEVEL OF EVIDENCE: Level IV, systematic review of mixed-level studies.